Related papers: Preferred-Frame and CP-Violation Tests with Polari…
We used a torsion pendulum containing $\sim 9 \times 10^{22}$ polarized electrons to search for CP-violating interactions between the pendulum's electrons and unpolarized matter in the laboratory's surroundings or the sun, and to test for…
We conducted a search for an exotic spin- and velocity-dependent interaction for polarized electrons with an experimental approach based on a high-sensitivity spin-exchange relaxation-free (SERF) magnetometer, which serves as both a source…
Experiments using macroscopic samples of spin-polarized matter offer exceptional sensitivity to Lorentz and CPT violation in the electron sector. Data from existing experiments with a spin-polarized torsion pendulum provide sensitivity in…
Very light particles with CP-violating couplings to ordinary matter, such as axions or axion-like particles, can mediate long-range forces between polarized and unpolarized fermions. We describe a new experimental search for such forces…
The existence of exotic spin-dependent forces may shine light on new physics beyond the Standard Model. We utilize two iron shielded SmCo$_5$ electron-spin sources and two optically pumped magnetometers to search for exotic long-range…
Electrons have an intrinsic, indivisible, magnetic dipole aligned with their internal angular momentum (spin). The magnetic interaction between two electrons can therefore impose a change in their spin orientation. This process, however,…
Terrestrial experiments that use electrons in Earth as a spin-polarized source have been demonstrated to provide strong bounds on exotic long-range spin-spin and spin-velocity interactions. These bounds constrain the coupling strength of…
New constraints on exotic dipole-dipole interactions between electrons at the micrometer scale are established, based on a recent measurement of the magnetic interaction between two trapped $^{88}$Sr$^+$ ions. For light bosons (mass $\le$…
Exotic spin-dependent interactions may be generated by exchanging hypothetical bosons that have been proposed to solve some mysteries in physics by theories beyond the standard model of particle physics. The search for such interactions can…
A new laboratory bound on the axial-vector mediated interaction between electron spins at micrometer scale is established with single nitrogen-vacancy (NV) centers in diamond. A single crystal of $p$-terphenyl doped pentacene-$d_{14}$ under…
We describe a proposal to search for an intrinsic electric dipole moment (EDM) of the proton with a sensitivity of \targetsens, based on the vertical rotation of the polarization of a stored proton beam. The New Physics reach is of order…
Exotic spin-dependent interactions between fermions have recently attracted attention in relation to theories beyond the Standard Model. The exotic interactions can be mediated by hypothetical fundamental bosons which may explain several…
The cross section which addresses the spin-flip transitions of a proton (antiproton) interacting with a polarized non-relativistic electron or positron is calculated analytically. In the case of attraction, this cross section is greatly…
Core-polarization interactions are investigated in low-energy electron elastic scattering from the atoms In,Sn,Eu,Au and At through the calculation of their electron affinities. The complex angular momentum method wherein is embedded the…
We report a search for exotic spin-spin interactions between neutrons and electrons which could signal new physics beyond the Standard Model using slow neutron polarimetric imaging through a dense medium of polarized electrons. Our dense…
The proton is a composite object with spin one-half, understood to contain highly relativistic spin one-half quarks exchanging spin-one gluons, each possibly with significant orbital angular momenta. While their fundamental interactions are…
We suggest a new spin orientation mechanism for localized electrons: $dynamic~electron~spin~polarization~provided~by~nuclear~spin~fluctuations$. The angular momentum for the electrons is gained from the nuclear spin system via the hyperfine…
Electron elastic scattering off a spin-polarized Cr(...$3d^{5}4s^{1}$, $^{7}S$) atom is theoretically studied in the region of electron energies up to $15$ eV using both a one-electron "spin-polarized" Hartree-Fock and multielectron…
We have constrained possible new interactions which produce nonrelativistic potentials between polarized neutrons and unpolarized matter proportional to $\alpha\vec{\sigma}\cdot\vec{v}$ where $\vec{\sigma}$ is the neutron spin and $\vec{v}$…
The Standard Model cannot explain the dominance of matter over anti-matter in our universe. This imbalance indicates undiscovered physics that violates combined CP symmetry. Many extensions to the Standard Model seek to explain the…